I'm from Indonesia. As you might haven't known, many of young generation of chinese-indonesia here can't speak chinese language especially the mandarin. In some places like sumatra or borneo, we can still find chinese indonesian speak hokkien or hakka. I want to learn mandarin and hokkien as well, I hope we can learn together.

welcome to the forum. As a student of Taiwanese, my own knowledge of Indonesian Hokkien is next to non-existent but I'm guessing other members will be able to answer most of your questions. As for Mandarin questions, I feel a bit more competent there and there are native speakers among our regulars, too. If you post a question to the Mandarin section, I'm sure you'll get answers. Although it seems to be not as active as the Hokkien one, at least I myself go and look from time to time. Concerning Hakka I'm afraid I don't know anything, but I seem to recall several of our regulars in the Hokkien section are active in the Hakka section as well, so I'm sure you will get answers there, too.

yeah, I remember when I signed up, I eventually wondered whether anything had gone wrong with my post so I reposted... so when it got approved, I had posted the exact same thing twice But don't worry, it seems only the very first post needs to be approved (or possibly the first new thread, not sure), so you should be fine now

Quite a number of the regulars here are specialized in Penang Hokkien, so I guess your question is in better hands with them than with me. In fact, I would be very interested in the dictionary suggestions myself because the closest thing I have to a Chiang-chiu dictionary is the Medhurst. And for various reasons, that is only of limited use for contemporary colloquial Hokkien. For one thing, it is outdated (published in 1832), lays its focus on literary readings instead of everyday speech, and also, Medhurst has never actually been to Chiang-chiu but composed the dictionary in Jakarta (then Batavia). For the last reason, it may actually be of interest to you, but I would advise you to use it with caution due to the other two reasons.If you want it nonetheless, it's on google books. The title is "A dictionary of the Hok-Këèn dialect of the Chinese language according to the reading and colloquial idioms" by Walter Henry Medhurst.

Is Medan Hokkien the "mainstream" Hokkien in Jakarta nowadays? I would expect there to be a lot of people there from Riau too, speaking a more Riau-Singapore type of Hokkien.

As for Penang-Medan Hokkien being Ciangciu-based, I think that's "overestimated". The "segmental" phonology (the sounds, but not the tones) are basically Ciangciu-style, but the tones are more of a Coanciu-type. The vocabulary and grammar are "wildly unique" w/i the world of Hokkien. Whereas mainstream Taiwanese has a Ciangciu bias in its vocabulary, Penang Hokkien does not seem to. It's worth keeping in mind that Penang Hokkien speakers today have much more Coanciu ancestry than Ciangciu. Basically, the orang Ciangciu arrived earlier and established the local culture before the mass arrival of orang Coanciu, who assimilated. But there is a lot of Coanciu DNA in the culture and language as well.

What U really need is a Penang-Medan-Phuket Hokkien dictionary, not a Ciangciu dictionary. That would not help U as much. U may have to travel to Malaysia to buy one. There are a few on the market and reviews seem to be mixed.